Large parts of Nevada and California experienced a loud explosion on Sunday morning as a result of a meteor.
The sound of the explosion around 8am prompted a flood of calls to law enforcement agencies on both sides of the Sierra Nevada in the two states.
The explosion rattled windows and shook houses from Reno to Winnemucca in Nevada, and from the Sacramento to Bakersfield areas in California.
Some people in the two states reported seeing a fireball streak across the sky at the same time.
Dan Ruby of the Fleischmann Planetarium at the University of Nevada, Reno, says the reports indicate the meteor broke up above Earth somewhere over the Sierra southwest of Reno.
When debris enters the atmosphere it creates explosions similar to the sonic boom of a fast-moving aeroplane, according to meteorologists.
There were no reports of earthquakes or other seismic activity at the time.